The invention relates to an optical sensor.
Windshield wiper systems for motor vehicles are known in which control of the windshield wipers is effected not only via a lever on the steering column but also via an optical rain sensor. The optical rain sensor typically includes a light source, whose electromagnetic radiation is reflected by the windshield differently, depending on the film of moisture on the windshield. The reflected proportion is detected by means of a photo element, so that an output signal of the rain sensor corresponding to the film of moisture can be furnished. These output signals can be evaluated in such a way and used for controlling the windshield wipers in such a way that both the turning on of the wiper system and the wiping speed are varied as a function of a measured quantity of rain.
Such rain sensors are typically disposed on the inside of the windshield. To avoid impairing the view for the driver, it is known to dispose the rain sensors in the region of an inside mirror, or in other words between the inside mirror and the windshield. The rain sensors are then disposed in a housing, which with a bottom face is in physical contact with the windshield. It is known to provide such housings with a polygonal or round bottom face. A disadvantage here is that with either a polygonal or a round bottom face, it is only with difficulty that the rain sensors can be integrated with a covering or fastening of an inside mirror; besides, they make the overall visual appearance of the arrangement less attractive. Precisely because these rain sensors are disposed at an exposed place in the motor vehicle, which can readily be seen both by someone using the vehicle and by those looking at the vehicle, the overall impression is adversely affected.